U2Python : PyCall from a subPackage

hello,

I try to call a method which is into a module which is into a package. 

on py I do : from package.subpackage import {*|module} 

Is there a syntax to do it with PyCallFunction('package.subpackage.module',mth,xx) or PyImport('package.subpacakge.module') ?? 

thanks for any help